FSC402H FORENSIC SCIENCE AND THE EXPERT December 2, 2003

Forensic Issues  Continuity  Quality Assurance  Accreditation  Expert Testimony

Continuity Continuity, Chain of Custody The procedures in place that account for the integrity, identification, and security of each specimen by tracking its handling and storage from its receipt to final disposition.

Continuity  Seals  Secure  Identity  Security  In transit  In storage  Receipt  Disposition

Continuity  Seals  Secure  Prevents tampering of the item  Provides a unique identifier of the item  Identity  Provides a unique identifier of the item

Continuity  Security  In transit  transferred from site to site by a staff member  transfer between areas (eg. CRO to toxicology) is from staff member to staff member  In storage  locked rooms  sealed containers

Continuity  Receipt * Record all information*  signs of tampering  item type, seal type, identifier #, attribution  initiate chain of custody  dates  initials  placement of integrity seals if not present

Continuity Disposition  disposal – biological samples  return to submitter – non-biologicals  under secure seal * MUST BE RECORDED

Quality Assurance  Those planned and systematic actions necessary to provide sufficient confidence that a laboratory's product or service will satisfy given requirements for quality.  Lab wide  Whole system

Quality Assurance Quality Control  Internal activities or activities according to externally established standards used to monitor the quality of analytical data and to ensure that it satisfies specified criteria.  e.g. quality control standard – a standard of known concentration to be tested in the method in question  may be internal or external

Quality Assurance Includes:  Use of validated procedures  Review of all results and reports  technical  administrative  Accreditation  Continuing Education

Quality Assurance Includes:  Use of proficiency testing  Comparative testing - analytical  Internal quality control samples - analytical  External quality control samples - analytical  Evaluation of Scientist  expert testimony  evaluation of reports

Quality Assurance Validation of Technical Procedures Quantitative ProceduresQualitative Procedures- specificity - accuracy - precision - linear range - limit of quantitation- limit of detection- ruggedness

Quality Assurance Specificity  ability to measure analyte in the presence of other compounds expected to be found in the matrix Ruggedness  can the method be duplicated  different days  different individuals

Quality Assurance Accuracy  closeness to the true value or expected value Precision  closeness to each other

Quality Assurance Limit of Quantification  lowest value accurately and precisely measured Limit of Detection  lowest value that can be distinguished from from background Linear Range  range over which standard curve is accurately and precisely linear

Accreditation PURPOSE To demonstrate that an organization has policies in place to  Assure quality  Detect deficiencies  Take corrective action

Accreditation PURPOSE To demonstrate that an organization’s management, operations, personnel, procedures, equipment, physical plant, security and health and safety procedures meet established standards

Accreditation SAY WHAT YOU DO DO WHAT YOU SAY

Accreditation ASCLD/LAB American Society of Crime Laboratory Directors Laboratory Accreditation Board

Accreditation  100% Essential  e.g. written or secure electronic chain of custody  70% Important  e.g. existence of a quality manual  50% Desired  e.g. general cleanliness/good housekeeping

The Expert Witness